Then there are the strategic and military dimensions. There may one day be another major war, or a large emerging nation could go rogue. But we cannot run Britain on a war footing. The Government should engage in contingency planning: it could stockpile steel, or even set up a couple of mothballed plants. None of this is any justification for nationalising unviable businesses.

But how much of a hammer blow to Britain’s independent warmaking (or defensive) capability would the closure of our remaining steel plants actually be?

The argument in favour of retaining significant steelmaking capacity is that we might need it in case of urgent re-armament or replenishment of lost military hardware. But the lead time for the construction of a Type 45 destroyer is 3 years – compared to one year for the groundbreaking HMS Dreadnought in 1906 and thirteen months for the famous HMS Belfast in 1938. While the aircraft carrier HMS Invincible was built in seven years during the 1970s, HMS Queen Elizabeth – first of the Royal Navy’s two new aircraft carriers – will have been in production and trials for eleven years before finally becoming operationally ready in 2020.

If we found ourselves facing a dire security or military threat requiring additional naval ships, besides directing our ire at David Cameron – who has presided over a shameful degradation of the Royal Navy’s surface fleet – Britain would have little choice but to attempt to buy the requisite ships from a foreign navy (who may or may not be willing to sell to us). The lead time for commissioning a modern advanced warship is now so long that most conflagrations would be over by the time new ships were completed. And all the time they were under construction, the shipyards – and steelworks, and any other supporting industry – building them would be vulnerable to sabotage from within and aerial attack from without.

In other words, the days when we could melt down iron railings and salvage bits of scrap material to aid the war effort or rush produce a battleship in eleven months are over (to the limited extent that they existed at all). In any future major war, Britain will effectively go to war with the hardware it has available at the time, with little prospect of rapid re-armament – which is why we should all be concerned about this supposedly Conservative government’s failure to prioritise defence spending.

These are not easy questions to answer. But in answering them, policymakers have an obligation to delve deeper than the very two-dimensional “steelwork closures will mean that Britain is no longer a military power” level of debate we are getting so far. And they have an obligation – not that they are likely to fulfil it – to be honest with the public about the trade-offs which guide such decisions.

As it happens, this blog would like to see more critical national security infrastructure brought back under British control – energy independence for a start, and a strengthened military with a Royal Navy befitting a powerful island trading nation. But so far, I have yet to be convinced by anyone that the loss of domestic steel production weakens us as a country any more than the many other inevitable global interdependencies which undergird our ability to make war – never mind the Conservative government’s reckless vandalism of the armed forces, which was utterly avoidable.

And so I put this out there to those with strong opinions backed up by detailed knowledge: from a national security standpoint, with so many other glaring (and often recently self-inflicted) weaknesses in our national security infrastructure, does the potential loss of our remaining domestic steel production capacity really matter?

Postscript:

This is not to say there should not be some type of government intervention to delay the steelworks closures or mitigate their effects. Surely one of the lessons learned from Thatcherism is that no matter how essential industrial and economic realignment may be for long-term success, simply expecting people (particularly a coddled British population used to being helped by the government) to brush themselves off and start lucrative new careers after being made redundant is callous and wildly overoptimistic. The word “Tory” is still utterly toxic in some communities, over thirty years later, and we must avoid making it even worse.

People have no right to demand that the state (i.e. their taxpaying neighbours) permanently subsidise the loss-making industry which gives them employment, but we should provide those affected with transitional support through re-training and educational grants to equip workers with more lucrative skills. Failing to do so, either out of bumbling incompetence (David Cameron and Sajid Javid) or rigid ideology will only create more negative consequences of social deprivation and regional dereliction, which is morally wrong as well as more expensive in the long term.